The line input on my Focusrite Scarlett Solo 3rd Gen interface is being fed by a ribbon mic through a dedicated high gain preamp (up to 72 dB). Should I keep the interface line input pot set at zero or crank it up a bit and decrease the preamp gain to prevent overdriving -- or does it make any difference? I'm trying to keep the noise floor as low as possible. Also, what about the "instrument" setting? Is that an impedance switch or does it activate an extra stage of amplification?